rs199472800

Variant summary

Our verdict is Pathogenic. The variant received 17 ACMG points: 17P and 0B. PM1PM5PP2PP3_StrongPP5_Very_Strong

The NM_000218.3(KCNQ1):​c.1664G>A​(p.Arg555His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000217 in 1,566,228 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 13/23 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R555L) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000023 ( 0 hom. )

Consequence

KCNQ1
NM_000218.3 missense

Scores

17
2
1

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:12O:1

Conservation

PhyloP100: 7.52

Publications

18 publications found
Variant links:
Genes affected
KCNQ1 (HGNC:6294): (potassium voltage-gated channel subfamily Q member 1) This gene encodes a voltage-gated potassium channel required for repolarization phase of the cardiac action potential. This protein can form heteromultimers with two other potassium channel proteins, KCNE1 and KCNE3. Mutations in this gene are associated with hereditary long QT syndrome 1 (also known as Romano-Ward syndrome), Jervell and Lange-Nielsen syndrome, and familial atrial fibrillation. This gene exhibits tissue-specific imprinting, with preferential expression from the maternal allele in some tissues, and biallelic expression in others. This gene is located in a region of chromosome 11 amongst other imprinted genes that are associated with Beckwith-Wiedemann syndrome (BWS), and itself has been shown to be disrupted by chromosomal rearrangements in patients with BWS. Alternatively spliced transcript variants have been found for this gene. [provided by RefSeq, Aug 2011]
KCNQ1 Gene-Disease associations (from GenCC):
  • long QT syndrome
    Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
  • long QT syndrome 1
    Inheritance: AD, AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
  • Jervell and Lange-Nielsen syndrome
    Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
  • Jervell and Lange-Nielsen syndrome 1
    Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: PanelApp Australia, Labcorp Genetics (formerly Invitae), G2P
  • atrial fibrillation, familial, 3
    Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
  • short QT syndrome
    Inheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: ClinGen, Orphanet
  • short QT syndrome type 2
    Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
  • familial atrial fibrillation
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • Jervell and Lange-Nielsen syndrome
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • hypertrophic cardiomyopathy
    Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 17 ACMG points.

PM1
In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 13 uncertain in NM_000218.3
PM5
Other missense variant is known to change same aminoacid residue: Variant chr11-2776033-G-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 940744.
PP2
Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 212 curated pathogenic missense variants (we use a threshold of 10). The gene has 12 curated benign missense variants. Gene score misZ: 1.8321 (below the threshold of 3.09). Trascript score misZ: 0.90233 (below the threshold of 3.09). GenCC associations: The gene is linked to short QT syndrome type 2, long QT syndrome 1, Jervell and Lange-Nielsen syndrome 1, long QT syndrome, short QT syndrome, Jervell and Lange-Nielsen syndrome, hypertrophic cardiomyopathy, familial atrial fibrillation, atrial fibrillation, familial, 3.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.99
PP5
Variant 11-2776033-G-A is Pathogenic according to our data. Variant chr11-2776033-G-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 53003.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNQ1NM_000218.3 linkc.1664G>A p.Arg555His missense_variant Exon 13 of 16 ENST00000155840.12 NP_000209.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KCNQ1ENST00000155840.12 linkc.1664G>A p.Arg555His missense_variant Exon 13 of 16 1 NM_000218.3 ENSP00000155840.2

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152214
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000654
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000227
AC:
4
AN:
176120
AF XY:
0.0000215
show subpopulations
Gnomad AFR exome
AF:
0.0000931
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000410
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000233
AC:
33
AN:
1414014
Hom.:
0
Cov.:
33
AF XY:
0.0000229
AC XY:
16
AN XY:
698562
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
32652
American (AMR)
AF:
0.00
AC:
0
AN:
36956
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25288
East Asian (EAS)
AF:
0.0000267
AC:
1
AN:
37500
South Asian (SAS)
AF:
0.0000125
AC:
1
AN:
80250
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
49470
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5536
European-Non Finnish (NFE)
AF:
0.0000257
AC:
28
AN:
1087590
Other (OTH)
AF:
0.0000510
AC:
3
AN:
58772
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.501
Heterozygous variant carriers
0
2
4
6
8
10
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152214
Hom.:
0
Cov.:
33
AF XY:
0.00
AC XY:
0
AN XY:
74364
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41446
American (AMR)
AF:
0.0000654
AC:
1
AN:
15288
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5196
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4838
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10630
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68028
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.575
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.0000165
Hom.:
0
Bravo
AF:
0.00000756

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:12Other:1
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Long QT syndrome Pathogenic:4
Nov 24, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with histidine, which is basic and polar, at codon 555 of the KCNQ1 protein (p.Arg555His). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This missense change has been observed in individuals with long QT syndrome (PMID: 14998624, 22949429, 23098067, 23130128). ClinVar contains an entry for this variant (Variation ID: 53003). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt KCNQ1 protein function with a positive predictive value of 95%. Experimental studies have shown that this missense change affects KCNQ1 function (PMID: 25037568, 25344363). This variant disrupts the p.Arg555 amino acid residue in KCNQ1. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 9386136, 19934648). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

Jan 16, 2024
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: KCNQ1 c.1664G>A (p.Arg555His) results in a non-conservative amino acid change located in the Potassium channel, voltage dependent, KCNQ, C-terminal domain (IPR013821) of the encoded protein sequence. This alters a highly conserved residue (HGMD) in which another missense variant (p.Arg555Cys) is classified as pathogenic. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 2.3e-05 in 176120 control chromosomes (gnomAD). c.1664G>A has been reported in the literature in multiple individuals affected with Long QT Syndrome (e.g. Lupoglazoff_2004, Giudicessi_2012, Yee_2022). These data indicate that the variant is very likely to be associated with disease. Publications report experimental evidence evaluating an impact on protein function, finding that the variant disrupts channel current (Ademuyiwa_2014, Dvir_2014). The following publications have been ascertained in the context of this evaluation (PMID: 14998624, 22949429, 25344363, 25037568, 36102233). ClinVar contains an entry for this variant (Variation ID: 53003). Based on the evidence outlined above, the variant was classified as pathogenic. -

Jan 15, 2024
Human Genome Sequencing Center Clinical Lab, Baylor College of Medicine
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Sep 24, 2024
All of Us Research Program, National Institutes of Health
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This missense variant replaces arginine with histidine at codon 555 in the C-terminal cytoplasmic domain of the KCNQ1 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). Functional studies have shown that this variant impairs sodium channel function without disrupting protein trafficking to the cell surface (PMID: 25037568, 25344363). This variant has been reported in individuals affected with long QT syndrome (PMID: 14998624, 19841300, 22949429, 23130128; ClinVar SCV000234515.13) and in individuals suspected of having long QT syndrome (PMID: 15840476, 19716085, 23098067). This variant has been identified in 4/176120 chromosomes in the general population by the Genome Aggregation Database (gnomAD). Based on the available evidence, this variant is classified as Likely Pathogenic. -

not provided Pathogenic:3
Jun 18, 2024
GeneDx
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 19716085, 23098067, 23130128, 26745405, 25705178, 22581653, 34505893, 34697415, 25037568, 19841300, 15840476, 14998624, 22949429, 27761162, 26412604, 9386136, 30609406, 32048431, 32383558, 31006312, 33087929, 25344363) -

Jul 10, 2021
Kariminejad - Najmabadi Pathology & Genetics Center
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jan 01, 2023
CeGaT Center for Human Genetics Tuebingen
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

KCNQ1: PM1, PM2, PM5, PS4:Moderate, PP3, PP4, PS3:Supporting -

Long QT syndrome 1 Pathogenic:2
Aug 01, 2023
Molecular Genetics Laboratory - Cardiogenetics, CHU de Nantes
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Dec 19, 2023
North West Genomic Laboratory Hub, Manchester University NHS Foundation Trust
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

PM1_Mod PP1_Mod PP3_Supp PS3_Mod PS4_Str -

Beckwith-Wiedemann syndrome;C1837014:Atrial fibrillation, familial, 3;C1865019:Short QT syndrome type 2;C4551509:Jervell and Lange-Nielsen syndrome 1;C4551647:Long QT syndrome 1 Pathogenic:1
Oct 16, 2021
Fulgent Genetics, Fulgent Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Cardiovascular phenotype Pathogenic:1
Feb 04, 2025
Ambry Genetics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.R555H variant (also known as c.1664G>A), located in coding exon 13 of the KCNQ1 gene, results from a G to A substitution at nucleotide position 1664. The arginine at codon 555 is replaced by histidine, an amino acid with highly similar properties. This alteration has been detected in individuals reported to have long QT syndrome (LQTS), and in several LQTS testing cohorts, although clinical details were limited (Lupoglazoff JM et al. J. Am. Coll. Cardiol., 2004 Mar;43:826-30; Tester DJ et al. Heart Rhythm, 2005 May;2:507-17; Kapplinger JD et al. Heart Rhythm, 2009 Sep;6:1297-303; Giudicessi JR et al. Circ Cardiovasc Genet, 2012 Oct;5:519-28; Stattin EL et al. BMC Cardiovasc Disord, 2012 Oct;12:95). Functional studies by different investigators have demonstrated reduced current, slower activation, and faster deactivation with this alteration, while conclusions about possible trafficking defects were conflicting (Dvir M et al. J. Cell. Sci., 2014 Sep;127:3943-55; Aromolaran AS et al. Cardiovasc. Res., 2014 Dec;104:501-11). Based on internal structural analysis, this variant is predicted to be structurally disruptive (Long SB et al. Nature. 2007 Nov;450(7168):376-82; Ambry internal data). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the majority of available evidence to date, this variant is likely to be pathogenic. -

Cardiac arrhythmia Pathogenic:1
Nov 18, 2024
Color Diagnostics, LLC DBA Color Health
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This missense variant replaces arginine with histidine at codon 555 of the KCNQ1 protein. This variant is found within a highly conserved region of the C-terminal cytoplasmic domain of the KCNQ1 protein (a.a. 509-575). Rare nontruncating variants in this region have been shown to be significantly overrepresented in individuals with long QT syndrome (PMID: 32893267). Functional studies have shown that this variant impairs potassium channel function without disrupting protein trafficking to the cell surface (PMID: 25037568, 25344363). This variant has been reported in over ten individuals affected with long QT syndrome (PMID: 14998624, 19841300, 22949429, 23130128, 32383558, 34505893, 36102233, 37457655, ClinVar SCV000234515.13) and in another few individuals suspected of having long QT syndrome (PMID: 15840476, 19716085, 23098067, 26412604). This variant has been identified in 4/176120 chromosomes in the general population by the Genome Aggregation Database (gnomAD). A different missense variant occurring at the same codon, p.Arg555Cys, is known to be pathogenic (ClinVar variation ID 3126), indicating that arginine at this position is important for KCNQ1 protein function. Based on the available evidence, this variant is classified as Likely Pathogenic. -

Congenital long QT syndrome Other:1
-
Cardiovascular Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust
Significance:not provided
Review Status:no classification provided
Collection Method:literature only

This variant has been reported as associated with Long QT syndrome in the following publications (PMID:14998624;PMID:15840476;PMID:19716085;PMID:19841300;PMID:15214551). This is a literature report, and does not necessarily reflect the clinical interpretation of the Imperial College / Royal Brompton Cardiovascular Genetics laboratory. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.98
CardioboostArm
Pathogenic
1.0
BayesDel_addAF
Pathogenic
0.56
D
BayesDel_noAF
Pathogenic
0.57
CADD
Pathogenic
33
DANN
Pathogenic
1.0
DEOGEN2
Pathogenic
0.99
D;.;.
Eigen
Pathogenic
0.77
Eigen_PC
Pathogenic
0.67
FATHMM_MKL
Uncertain
0.92
D
LIST_S2
Pathogenic
0.98
D;D;D
M_CAP
Pathogenic
0.94
D
MetaRNN
Pathogenic
0.99
D;D;D
MetaSVM
Pathogenic
0.90
D
MutationAssessor
Pathogenic
3.1
M;.;.
PhyloP100
7.5
PrimateAI
Pathogenic
0.83
D
PROVEAN
Uncertain
-4.4
D;.;D
REVEL
Pathogenic
0.92
Sift
Pathogenic
0.0
D;.;D
Sift4G
Pathogenic
0.0
D;.;D
Polyphen
1.0
D;.;D
Vest4
0.99
MutPred
0.96
Loss of MoRF binding (P = 0.0076);.;.;
MVP
0.99
MPC
1.3
ClinPred
0.99
D
GERP RS
3.8
Varity_R
0.85
gMVP
0.99
Mutation Taster
=3/97
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.0
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs199472800; hg19: chr11-2797263; API